Laser time-transfer facility and preliminary results from the CHOMPTT CubeSat mission

Abstract

The CubeSat Handling of Multisystem Precision Time-Transfer (CHOMPTT) mission is a precision timing and laser time-transfer demonstration on a CubeSat in orbit. Developed by the University of Florida in collaboration with NASA Ames Research Center, the 3U CubeSat has been in orbit for over 3 years and has attempted time-transfer operations to three satellite laser ranging (SLR) facilities. Additionally, the CHOMPTT CubeSat has successfully achieved one of its two primary goals, the first-ever measurement of the relative timing performance (Allan deviation) of Chip Scale Atomic Clocks (CSAC) on-orbit, while time transfer operations continue. The on-orbit performance of the CSACs and host payload is consistent with pre-flight measurements on the ground, with the CSAC timing stability exceeding the manufacturer specification by roughly a factor of three, or an Allan Deviation of 100 ps over 1 s of averaging time compared to a datasheet value of 300 ps over the same timeframe. This paper discusses the CHOMPTT spacecraft’s performance on-orbit relative to ground experiments performed prior to launch, as well as the design and operation of the laser ranging facility and spacecraft flight operations performed during the mission’s lifetime.